Dispensing device for viscous materials



Aug. 3, 1948. w. J. WEBER DISPENSING DEVICE FOR VISCOUS MATERIALS Filed Dec. 6, 1944 f/G. Z I

INVENTOR. Mu/AM f Mam Patented Aug. 3, 19 48 UNITED STATES PATENT 2,446,501

nisritivsmg lg l i l g lgggit viscous William J. Weber,- Lyndhurst, Ohio, assignor to Samuel Crewe, Cleveland, Ohio Application December 6, 1944, Serial No. 566,879

1 Claim. 1 This invention relates to pneumatic guns and particularly to guns used for dispensing caulk, grease or similar viscous materials.

Conducive to a clearer understanding of the invention, it may be well to point out that prior art air guns capable of dispensin thick plastic caulk are comparatively complicated, relatively expensive and diflicult to manufacture and use. All of them require considerable air pressure to make them operate efficiently and none of them has an auxiliary manually operable means which permitted an external force to be used to assist or supplement the air pressure operating the gun when, under certain circumstances, extra force is needed.

It is therefore the primary object of this invention to provide a gun which ejects material therein by the action of either air pressure or manual operation and which may inject material by manual operation alone.

Another object of this invention is to provide a simple and inexpensive pneumatic type caulk gun which is light in weight and easy to hold and use.

A further object is to provide a device of the type mentioned with an adjustable automatic pressure control valve so that the plastic caulk therein may be ejected under different degrees of pressure.

These and other objects of the invention will become apparent from a reading of the followin description and claims, together with the accompanying drawing, in which like parts are referred to andindic'ated by like reference characters, and wherein:

Figure 1 is a side elevational view of the novel pneumatic caulk gun constituting this invention, with parts broken awa to show its construction;

Figure 2 is an enlarged portion of the caulk gun barrel, partly in section and showing the double-acting piston and rod therein;

Figure 3 is an enlarged view of the valve portion of the handle, partly in cross section and showing its construction;

Figure 4 is a vertical sectional view of the gun handle, taken substantially along the lineand in the direction of the arrows 4'-'-4 of the Figure 3; and

Figure 5 is a vertical cross sectional View ofthe air flow control valve used in the gun and particularly showing the relative positions of parts wh'enin its open position. The pneumatically operated caulk gun constituting this invention consists primarily of three elements; the cylinder 0r barrel, the plunger therein and the handle attached thereto. Each of these elements will be described in detail here'- inafter and in the order just set forth,

The barrel l0 consists of a cylindrical tube having an external thread l2 on its front end and. similar external threads 13 on its rear end. The rear inner portion of the cylinder, the portion back of the hereinafter described piston, forms an air chamber and is indicated in the drawing by the reference character ll.

Attached to the front end of the cylinder l0 there-is a nozzle member M. This member has a tapered and constricted portion I5 on the front end thereof for directing the plastic caulk as desired. The nozzle portion also has an internally threaded flange portion it which separably en gages the threads l2 of the cylinder.

The plunger member consists of a pair of op' positely facing pliable leather or fiber cups l8 and I9. Each of these cups has a flange portion which tightly fits the inside wall of the cylinder in. The fabric cups [8 and I9 are mounted on the threaded front end of the piston rod I! by means of the two facin metal discs 2i and the two nuts 22. The forward piston cup I8 is in the compartment of the barrel containing the caulk and has its flange facing toward the nozzle l4. Its' flange has a tendency to flare or spread outward and thus make closer contact with the inner wall of the cylinder when the piston is moved forward, either by the action of the air in the chamber H or by" the forward manipulation of the piston rod H. The rear piston portion l9 rides in the air chamber H and its flange faces the handle of the gun. It therefore has a tendency to flare or' spread when drawn rearwardly by the wall. The outer end of the rod ll, the end opp'osite the piston, is provided with a cross arm 23 for convenience in handling and operating the ull;

The handle member may be made of cast metal, plastic or other suitable material and consists of a comfortably shaped grip portion 3| and a valve portion 36 integral therewith. The grip portion Si is a hollow element having a broad chamberlike air passage 32 and a narrow air passage 42' therein which connects the air supply with the hereinafter described air flow control valve. The bottom end of the grip portion has a threaded opening 33 in the chamber 32 which receives thethreaded connection 34 on the air hose 35.

The valve portion 36- of the handle member has at its forward end a flared or hell portion 31 which terminates in an internally threaded flange 38 which receives the external threads l3 of the barrel l0. Running longitudinally through the valve portion 36 there is an air passage 39 which is concentric with the cylinder l and the piston rod 17. The inside diameter of this axial or longitudinal air passage 39 is about twice the outside diameter of the piston rod 11. The piston rod I! is therefore able to freely move longitudinally therethrough and still allow plenty of space therearound for air to pass into the chamber H from the grip portion below.

A finger-operable valve 45 is mounted in the valve portion 36, as is clearly shown in the Figure 3. This air flow control valve 45 is a unit in itself 4 and is compressed by the adjacent tapered inside end of the cap 54.

When the cap 54 is screwed tighter on the threads 50, the collar 51 will have a tendency to more closely bind or seal the rod 11.

For a proper appreciation of this invention, it should be borne in mind that this gun is designed to be steadily moved alongand to simultaneously, speedily and thoroughly discharge thick, plastic caulk into cracks, holes, seams and the like. Since all cracks or holes are not of the same depth or and screws into the opening 40 in the handle.

The chamber or opening 40 in the handle member.-

lies between the upper vertical air passage 4| and the lower vertical air passage 42. The valve seat,

43 is formed in the opening 4!! between the passages M and 43 and normally receives the movable valve closure or ring 44. The expansion spring 46 tends to keep the valve in its normally closed position. When the finger button is pressed and the valve is opened, the valve ring 44 is unseated from the portion 43 and air under pressure is thus permitted to flow through the air hose 35, through the passages 32, 42, 41 and 39, and into the air chamber H in the cylinder, causing the plunger tomove forward.

In order to provide a constant airpressure for the gun, an automatic air pressure controlvalve is mounted on the top of the handle where it may be conveniently reached with the operators thumb. This automatic valve has an externally threaded portion which screws into the valve portion 36, as shown in the Figure 3. This valve element also has a vertical airpassage 41 therein which opens into the longitudinal air passage 39. It has a cap 48 which has a small vent 49 in the top thereof. This cap 48 is threadedly engaged with the lower portion of the valve element and contains a small ball 25 and a spring 26 which normally tend to close the vertical air passage 41. The weight or tension of the spring 26 may be varied easily by screwing or'unscrewing the cap 48 on the lower valve portion. In this manner the pressure of the air in the longitudinal air passage 39 may be regulated during the dispensing operation in accordance with the immediate requirements. At a certain point, whenthe pressure of the air in the air passage 4'! exceeds the tension of the spring, 26, the ball 25 will rise and the excess air will flow out through the vent 49 and the pressure in the chamber H is thereby lowered correspondingly. V

The air seal used in the handle member and in conjunction with the movable piston rod l1 consists of an externally threaded tubular member 5| which fits the threaded opening in the handle aligned with the longitudinal air passage 39 and where the piston rod IT projects outwardly therefrom. This seal also has an externally threaded portion 53 which is engaged by the internally threaded cap 54. 'The cap 54 has an axial opening for the piston rod 1 l to project therethrough. Inside the seal 5| and the cap 54 there is a constrictive collar 51 which snugly fits the piston rod l I, just forwardly of the opening 56 in the cap 54. This constrictive collar 51 is made of fiber or other suitable packing material and is capable of making an air tight seal aroundthe rod l! but yet does not bind it sufliciently to prevent the rod I! from easily and smoothly sliding therethrough. The collar 51 also has an enlarged or beaded portion which is bevelled as shown and which fits size and since their characteristics are not readily discernible to the eye, it sometimes becomes necessary to speed the ejection of the material when the crack or hole is deep and conversely to decrease the speed of its ejection when the crack is shallow or short. A single steady flow of material does not therefore spread evenly. This is just contrary'to the desired action of a conventional grease gun that is used for filling a single reservoir at a single special opening and at one predetermined pressure. t

The adjustable automatic pressure control valve and the double-acting rod and piston, therefore, make it possible to use this air gun for the special ejection of caulk and for its more frequent refilling, for which the prior art guns are not Wholly practical.

Having thus disclosed the invention in its preferred form, it should be understood that thedevice as described and illustrated is not to be considered in a limited sense as there may be other forms or modifications thereof which may also be regarded as being within the scope of the appended claim.

I claim:

In a dispenser of the gun type, a barrel having a discharge opening at its forward end and an open rear end, a piston slidable in said barrel, a piston rod having its forward end connected to said piston and having its rear end extending through said open rear end of the barrel, a unitary rear end handle structure for closing the open rear end of the barrel about said piston rod and having an elongated passage alined with and communicating with said barrel through which said rear end of the piston rod extends, said elongated passage being of substantially greater diameter than the piston rod, a nipple disposed over the rea'rwardly extending end of the piston rod and having its forward end detachably secured to therrear end handle structure and having a passage alined with said first-named elongated passage, a packinglmember secured to the rear end of the nipple about said piston rod inwardly of the rearwardly extending end of the latter, and a handle secured to the free rear end of the piston rod.

. WILLIAM J. WEBER.

. REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number 2,129,801 'Wa1lace Sept. 13, 1938 

